the second largest known
body of liquid on Saturn's moon Titan.
There are a lot of interesting new pieces of information in the map but perhaps the most tantalizing is that Titan has a global sea level like Earth.
The research is published in two separate Geophysical Review Letters papers, one focusing on the sea levels and the other (Titan's Topography and Shape at the end of the Cassini Mission) describing the detailed map of the moon.
The map combines all the Titan typography data available from multiple sources, such as high-resolution images, to produce an interpolated analysis of what the full surface of the moon is likely to look like.
Titan is the only other object in the Solar System that has stable liquid on its surface, although instead of being water it's hydrocarbons; mostly liquid methane and ethane.
The Cassini probe was able to measure the sea level to a staggering precision and realized that it was consistent around the moon.
Having a global sea level has a very important consequence.
It implies that liquid hydrocarbons flow under the surface of Titan, just like water flows through porous rocks in aquifers here on Earth.
The team considered lakes, ancient lakes, and watersheds across the surface, and the data seems to be in agreement with their hypothesis.
The study doesn't just answer questions, though, it also creates a new mystery.
Most of Titan's lakes are located in sharp-edge depressions with ridges hundreds of meters high. The peculiar shapes were described by the team as looking like they were created by cookie cutters.
Understanding their formation is key to having a clear picture of the methane cycle on the moon.
Only 9 percent of the whole moon has been mapped in high-resolution, while 25 to 30 percent was imaged in lower resolution. The topography for the rest of Titan was interpolated with state-of-the-art algorithms.
Armed with this the researchers were able to discover two locations near the equator that could be old lakes or cryovolcanic flows, and a few new mountains, although none taller than 700 meters (2,300 feet).
Cassini is unfortunately not there anymore to collect more data so, for now, researchers will have to use lab simulations and what has been observed so far to work it all out.